Pole vaulting is a particularly strenuous sport, with each jump placing considerable strain on the physical body of the vaulter. Most of the strain arises as the vaulter is utilizing the inertia of his initial run and the strength in his arms to swing his body through an arc into a upside-down position on the pole, just prior to passing over the cross-bar. In this position, the vaulter is "standing on his hands", with the hands gripping the pole. The final "kick" to get the vaulter over the cross-bar comes partly from the pole itself, which nowadays is a fibreglass pole with considerable resilience and capacity for bending.
In performing his jump, the vaulter firstly paces off his "run" backward from the vaulting box, which is normally a fixed box recessed into the ground or track. The box is typically wedge-shaped with a gradually increasing depth into the ground in the forward direction, while the sides converge in the forward direction. The vaulter, holding the pole toward the upper end, then commences his run toward the vaulting box with most of the pole being held forwardly in front of him.
Running close to or at his top speed, the vaulter places the leading end of the pole into the vaulting box and at the same time executes the "take-off", which typically involves leaping off the ground usually on his left foot, at the same time swinging the right foot forwardly and upwardly in order to take advantage of the inertia of his running speed. With such a take-off, the vaulter swings past the pole to the right of the pole, pulling himself up to a position in which his arms and hands are at the bottom and the remainder of the body extends upwardly from the hands.
Between the take-off and the latter "handstand" position, the conventional fibreglass pole will normally bend through a considerable arc. By the time the vaulter reaches the "handstand" position, the pole is beginning to straighten itself out, and in so doing it gives an additional upward thrust to the vaulter's body, which is utilized to gain extra height in the jump.
An extremely critical point in the jump is the take-off just described. In the take-off, the vaulter must propel his body into the jump at just the right speed and from just the right position with respect to the vaulting box. Because the position of take-off is so critical, the run up to the vaulting box is also of extreme importance to making a good jump. If a vaulter, in practicing his sport, were required to execute a complete vault every time he attempted to work on the take-off or the run up to the box, he would become exhausted very quickly, and probably no more than a dozen or so such attempts could be made at any one time.